What is a Quinella?

A quinella involves selecting the first two finishers in a race, and is considered a 'boxed' or combination bet. Since the finishing order doesn't matter, selecting two horses doubles your chances of winning. For example,

If you wager on the #3 and #8 horses, your bet will be graded as a win if the first two finishers are 3-8 or 8-3.